TY - JOUR
T1 - Unraveling the Effect of Conformational and Electronic Disorder in the Charge Transport Processes of Semiconducting Polymers
AU - Chew, Annabel R.
AU - Ghosh, Raja
AU - Pakhnyuk, Viktoria
AU - Onorato, Jonathan
AU - Davidson, Emily C.
AU - Segalman, Rachel A.
AU - Luscombe, Christine K.
AU - Spano, Frank C.
AU - Salleo, Alberto
N1 - Funding Information:
The authors acknowledge financial support from the National Science Foundation under DMREF—1533987, 1533372. C.K.L. acknowledges financial support by the NSF DMR1708317. The P3HT samples were synthesized in part upon work supported by the State of Washington through the University of Washington Clean Energy Institute and via funding from the Washington Research Foundation. R.A.S. acknowledges financial support from the Department of Energy Office of Basic Energy Sciences under Grant No. DE-SC0016390. This research reported here made use of shared facilities of the UCSB MRSEC (NSF DMR 1720256).
Funding Information:
The authors acknowledge financial support from the National Science Foundation under DMREF?1533987, 1533372. C.K.L. acknowledges financial support by the NSF DMR1708317. The P3HT samples were synthesized in part upon work supported by the State of Washington through the University of Washington Clean Energy Institute and via funding from the Washington Research Foundation. R.A.S. acknowledges financial support from the Department of Energy Office of Basic Energy Sciences under Grant No. DE-SC0016390. This research reported here made use of shared facilities of the UCSB MRSEC (NSF DMR 1720256).
Publisher Copyright:
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2018/10/10
Y1 - 2018/10/10
N2 - Charge transport in semiconducting polymers is inextricably linked to their microstructure, making the characterization of polymer morphology at all length-scales essential for understanding the factors that limit mobility in these materials. Indeed, charge transport depends both on the ability of polarons to delocalize at the approximately nanometer length-scale and navigate a complex energetic and morphological mesoscale landscape. While characterization of the mesoscale morphology of polymers is well-established, studies of the local chain packing and nanoscale disorder, which affect delocalization, can be significantly more difficult to carry out. Through infrared charge modulation spectroscopy and theoretical modeling, the effect of the local chain environment on polaron delocalization is directly measured and quantified. Using a series of polymers based on the model system, poly(3-hexylthiophene), the link between disorder and polaron localization is systematically explored. Polaron delocalization is correlated with known trends in mobility, revealing that while charge delocalization is always beneficial, the formation of tie-chains is necessary to reach the highest mobilities in semicrystalline polymers. The results provide direct evidence for the importance of both nanoscale (charge carrier delocalization) and mesoscale (tie-chains) orders, demonstrating the need to distinguish the key length-scale limiting charge transport in the design of new, high mobility polymers.
AB - Charge transport in semiconducting polymers is inextricably linked to their microstructure, making the characterization of polymer morphology at all length-scales essential for understanding the factors that limit mobility in these materials. Indeed, charge transport depends both on the ability of polarons to delocalize at the approximately nanometer length-scale and navigate a complex energetic and morphological mesoscale landscape. While characterization of the mesoscale morphology of polymers is well-established, studies of the local chain packing and nanoscale disorder, which affect delocalization, can be significantly more difficult to carry out. Through infrared charge modulation spectroscopy and theoretical modeling, the effect of the local chain environment on polaron delocalization is directly measured and quantified. Using a series of polymers based on the model system, poly(3-hexylthiophene), the link between disorder and polaron localization is systematically explored. Polaron delocalization is correlated with known trends in mobility, revealing that while charge delocalization is always beneficial, the formation of tie-chains is necessary to reach the highest mobilities in semicrystalline polymers. The results provide direct evidence for the importance of both nanoscale (charge carrier delocalization) and mesoscale (tie-chains) orders, demonstrating the need to distinguish the key length-scale limiting charge transport in the design of new, high mobility polymers.
KW - carrier mobility
KW - charge delocalization
KW - charge transport
KW - polarons
KW - structure–property relationships
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U2 - 10.1002/adfm.201804142
DO - 10.1002/adfm.201804142
M3 - Article
AN - SCOPUS:85052384540
SN - 1616-301X
VL - 28
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 41
M1 - 1804142
ER -